Therapeutic device



' 16;1952 R. w. HODGSON ,62

THERAPEUTIC DEVICE Filed Sept. 4, 1945 5 Sheets-Sheet 5 ATTORNEY Patented Dec. 16, 1952 THERAPEUTIC DEVICE Robert W. Hodgson, Sherman Oaks, Calif., as-

signor to Herman S. Pierce, Los Angeles, Calif.

Application September 4, 1945, Serial No. 614,359

2 Claims. 1

This invention relates broadly to an oscillation generator and relates in particular to an apparatus for treatment of nerves and muscles by means of electric impulses, especially for artificial invigoration and stimulation of muscles for therapeutic purposes.

Therapeutic devices capable of generating currents of varying potential have been used for the treatment of various physiological disturbances.

' The apparatus employed heretofore has been extremely complex, required the use of a large number of electronic tubes, and was provided with so many controls, indicators and the like that a patient could not procure the equipment and use it for self-treatment due to the dangers involved in handling apparatus capable of generating a tremendous range of frequencies of various potentials. The present invention is particularly directed to a simple and compact apparatus which may be built economically so as to generate or produce a current of the desired characteristics or a current falling within relatively narrow limits of variation, so that an individual patient may keep the apparatus at his home for self-treatment.

Furthermore, the apparatus of the present invention is relatively foolproof, the terminals from the apparatus being virtually interchangeable without destroying the efiicacy of the current supplied to the electrodes.

It is an object of the present invention to provide a simple, small, compact and economical apparatus which will produce a therapeutic current giving better, quicker and more lasting results than those currents now employed therapeuti cally for a similar purpose.

It is a further object of the invention to provide an apparatus which will produce a therapeutic current which will cause nerve excitation and propagation with the minimum power dissipation in the form of heat created in the body tissues.

Another object of the'invention is to provide an apparatus for producing a therapeutic current, the current comprising separate pulsations spaced apart by periods of rest, the duration of the pulsations and the duration of the periods of rest between the pulsations being such as to cause nerve excitation and propagation with the minimum power dissipation in the form of heat created in the body tissues and without causing tetany in the muscle being treated.

Further objects of the invention include the provision in the device of means for intermittently interrupting the waveetrain and also mod- 34, condenser 35 and conductor 21. 30 of the electron tube I9 is also connected to ground at 25 by conductors 3| and 36, the priulating said wave train, each function being independently controlled.

Further objects and advantages of the invention will be brought out in the following part of the specification.

Referring to the drawings, which are for illustrative purposes only:

Fig. 1 is a schematic electrical circuit diagram showing a preferred embodiment of the device for producing the novel therapeutic current.

Fig. 2 is a' schematic electrical circuit diagram showing a second embodiment of the device.

Fig. 3 is a schematic electrical circuit diagram showing a third embodiment of the device.

In the preferred form of my device shown in Fig. 1, an alternating current supply circuit, such as the common volt alternating current commercial system, feeds the primary winding I of a transformer 2. One end of the secondary winding 3 of the transformer 2 is connected by a conductor 4 with one anode 5 of a full wave rectifying electron tube 6. The other end of the secondary winding 3 of the transformer 2 is connected by a conductor 1 with the other anode 8 of the full'wave rectifying electron tube 6. A-center tap 9 of the secondary winding 3 of the transformer 2 is connected to ground at I0. Another secondary winding I I of the transformer 2 is connected by conductors I 2, I3, and I4 with the filament I5 of the full wave rectifying electron tube 6 and by conductors I6 and I1 with the filament I8 of the electron tube I9 for energizing said filaments. The filament I5 of the full wave rectifying tube 6 is connected by conductors I3 and 20 with a choke coil 2|, which is connected by conductors 22 and 23 with a filter condenser 24,

which is connected to ground at 25 by conductors 26 and 21. The choke coil 2| is also connected by conductors 22 and 28 with load resistor 29, which is connected with the anode 30 of the electron tube I 9 by conductor 3 I.

The choke coil 2| is also connected by conductors 22, 28, and resistor 32 to the screen grid 33, which is connected to ground at 25 by conductor The anode mary winding 31 of the transformer 38, condenser 39, and conductors 40, 26, and. 21. The control grid 4| of the electron tube I9 is connected to ground at 25 by a resistor 42 and a conductor 43, in parallel with conductor 44, sec- 3 to ground at by a resistor 49 shunted by a condenser 59. The anode of electron tube I9 is also connected to ground at 25 by conductor 5|, condenser 52, potentiometer 53, and conductors 54, 41, 4B, 26 and 21'. The output lead 55 of the potentiometer 53 is interrupted by a switch 56 which is mechanically connected to a switch 51 of an intermittent action, electromagnetic time delay relay 58, one terminal of which is connected in series with the switch 51, the conductor 59, the resistor 65, and the choke coil 2!, and the other terminal of which is grounded at 50. The relay 58 is shunted by condenser 6|.

The device operates as follows:

When alternating current flows in the primary winding I of the transformer 2, a current is induced in the secondary winding lI-which energizes the filaments l5 and I8 of the full wave rectifying electron tube 5 and the electron tube 19 respectively. A flow of current is also induced in the secondary winding 3 which'is rectified by .full wave rectifying electron tubefi in a manner well known in the art. This rectified current is then filtered-by choke coil 2| and filter condenser 24 in a manner also well known in the art.

The greater the current flow through electron tube [9, the less positive the anode 30 becomes withrespect'to ground, and conversely, the lesser the current-flow through electron tube [9, the more positive the anode 30 becomes with respect to-ground. "With the'potential of the anode 30 thus fluctuating-with respect to ground, there is a corresponding currentfiow ina direction determinedzby the fluctuation of the potential of the anodei3lL-through primary winding 31 of "transformer-"38 andinto or out of condenser 39. This current fiow'through theprimary winding 31 of *the transformer '39 induces a current flow through the secondary winding 45 of the transformer 38 which charges condenser 46 with the same polarity as condenser 39. Thus'as greater ourrentilows through .the electron tube l9, a greater positive potential is applied to the control grid II, which .in turnallows a greater current to flow through the electron tube I'9, thus giving an extremely rapidrise in the current flowing through the electron tube ['9 until saturation current is 'flowing through the electron tube l9.

As soon as the condenser 39 becomes charged :to'a poteritial equal to the potential of the anode 3U when saturation current is flowing, all of the current flow through the primary winding 3'! of the transformer 38 ceases. As soon as the potentialof condenser 46 becomes greater than the induced potential across the secondary winding 45 of the transformer 38, which is of opposite polarity, the condenser 46 begins to discharge current in a direction opposite to the previous current flow through the secondary winding 45 of the transformer 38. This applies a negative potential to the grid 4 l, which reduces the current flow through the electron tube l9 which, in turn, causes the-anode 30 of the electron tube [9 to .become more positive, which causes an oppositely directed current flow through the primary wind- .ing'31 of the transformer 38 which,in turn, in- 'duces a current flow through the secondary winding 45 of the transformer 33, supplementing the currentflow resulting from the discharge of condenser 45, thus causing the current flow through the electron tube I9 to drop abruptly. It should be:noted thatthe current flow through the primarywindingS'l of the transformer 38 caused by themorepositive potential of the anode 30 of the ='.e1e.c,tron tubev 19, resulting from the reduction in 4 current flowing through the electron tube III, induces a voltage across the secondary winding of the transformer 38, which acts to effectively charge the condenser 46 through the resistance 42 to a polarity opposite to that which said condenser has previously had. The screen grid 33, associated condenser 35, resistor 32, and the biasing resistor 49 shunted by the by-pass condenser 50 all function in a manner well known in the art. The resistor 42 controls the rate of charging and discharging of the condenser 45.

The operation of the device described to this point-will result in a series of unidirectional, flattopped pulsations of substantially rectangular wave form acrossthe load resistor 29. A diiferentiating circuit comprising conductor 5|, con- .denser52, potentiometer 53, and conductors 54,

ll, 40, 26 and 21 differentiates said rectangular pulsations in a manner well known in the art and produces in potentiometer output lead 54 a series of pulsations sharply peaked in one direction. The potentiometer output load .is intermittently interrupted by the switch 516, which-is .mechanically connected :to the switch-51 of the intermittent action electromagnetic time :delay relay 58. The switch 51 is normally held incontact with the'contact point 62 by 'a spring (not shown). The current flows through theicon'ductor 59, the resistor 65, contact point 62,-:switch51 and into condenser -61 until said condenser is charged to a sufiic'iently high potential to cause the relay-5-8 to attract the switch 5'l and break'the circuit. The-circuit will bebrough't back to'iits normalposition'in contact with the contact point 52 by aspring (not shown) when the condenser "pulsations 'to'have-a gradually increasing amplitude up to the maximum value and then have a gradually decreasing amplitude until the wave train is interrupted bythe switch'56". This takes place by reason of the fact that the positive potential'at the anode'SD of the'electron tube I9 is intermittently interrupted by means of the switch 5F, which 'is positioned in the lead 22' prior to the juncture therewith of the 'filter condenser 24. Thus, when the switch 56' interrupts the circuit, a progressively decreasing positive potential is applied to the anode 30', which decreases at a rate dependent upon the time constant of the filter condenser and the circuit. This causes the oscillations generated to progressively decrease in amplitude also. When the switch 55 is closed, the positive potential applied through the choke filter comprising the choke coil 2| and the filter condenser 24 is progressively built up, which causes the oscillations generated in the oscillation generator to also have a progressively increasing amplitude. The rate of this modulation or building-up and decline of the oscillations generated in the oscillation generator maybe varied byvarying the time constant of a power supply filter.

Under some circumstances a rectangular wave formcmay be the most desirable and inthis connection :it is to be understood that the differenacaazoo tiatlng circuit shown in Fig. 1, comprising conductor condenser 52, potentiometer 5 3, may be dispensed with entirely, and as shown in Fig. 3 load resistor 29 may be replaced by a potentiometer 29" and potentiometer output lead 55 may be placed in contact with the potentiometer 29"". The switch 56" may be placed in the potentiometer output lead-55" or-- in the power circuit, for example, conductor 28",as hereinabove set forth.

The apparatus may be used in supplying electric impulses to various electrodesapplied to the human :body for therapeutic purposes. It has been used with particular success in relieving congestion of the prostate.

"When used in prostate treatment, an electrode is provided with means limiting its intro-- duction into the anus to a desired depth only, and an insulating sleeve which exposes only a desired, round-nosed electrode to contact with the membranes. This electrode is usually connected to terminal 53 of the device, whereas terminal 64 is usually connected to another electrode, preferably in the form of a moistened pad which is placed over the sacrum. However, the first mentioned electrode may be connected to terminal 64 and the second mentioned electrode may be con- 42-5375 megohms 49300 ohms 29-50,000 ohms 32-25,000 ohms 65-6,000 ohms 53-025 megohm 50-8 microfarads 35-01 microfarad 24 8 microfarads 39-0.02 microfarad 460.02 microfarad 520.02 microfarad 6 |250 microfarads 58-60 volts, 5000 ohms 2 l--15 henries The foregoing description serves merely to illustrate by specific applications the principles of my invention and should not be taken as defining the scope thereof. The oscillation generator described herein, is referred to in the claims as a self-excited feed back type, relaxa tion, electric oscillation generator. adapted to generate non-sinusoidal unidirectional electric oscillations of virtually rectangular wave form. This is understood to mean the type of oscillator wherein the frequency of the output oscillations is determined by an RC circuit and wherein there is a definite feed back from the output to the input. The wave form may vary from virtually rectangular to various other non-sinusoidal, unidirectional wave forms, and all such are to be understood to 'be included in the scope hereof.

I claim:

1. In a device adapted to generate therapeutic current, a feed back, self-excited, relaxationtype, single vacuum tube, electric oscillation generator adapted to generate non-sinusoidal, unidirectional electric oscillations without requiring an input signal from an external source, comprising: a thermionic electron tube means having a cathode, an anode and the control grid;

an anode circuit connecting said anode and cathode in series and'having a load impedance therein; a feed back transformer having a pri-- mary winding and a secondary in inductive relation; a condenser connecting one end of said primary winding to said cathode, the other end of said primary winding being connected to the anode; a grid biasing control circuit including a resistance and a capacitance, electrically connected to said secondary winding; said control grid andsaid cathode being connected to said control circuit so as to be on each side of said resistance; said feed back transformer and the load impedance in the anode circuit which causes a pulsating potential tobe applied to the primary winding, being such as to cause the secondary winding to alternately apply'a negative potential to said grid suificientlylarge to block the flow of current through the electron tube, and a positive potential sufiiciently large to cause saturation current to flow through said electron tube at a frequency determined by the time constant of the resistance and capacitance in the grid control circuit; an intermittent interrupting means arranged to effectively, intermittently interrupt the output oscillations of the oscillation generator, comprising a relay shunted by a condenser connected to the anode circuit through a resistance, said relay being arranged to simultaneously open a switch in said anode circuit in series with a power supply filter and a switch in series with said relay which is norm-ally spring biased into closed position, thus de-energizing the relay and allowing said switches to close, which causes the relay to be energized again and open the switches intermittently in a manner dependent upon the time constant of said interrupting means whereby the oscillations generated by the oscillation generator are caused to increase to a maximum and decrease to a minimum upon opening and closing of said switch at a rate of increase and decrease dependent upon the time constant of the power supply filter.

2. In a device adapted to generate therapeutic current, a feed back, self-excited, relaxation-type, single vacuum tube, electric oscillation generator adapted to generate non-sinusoidal, unidirectional electric oscillations without requiring an input signal from an external source, comprising: a thermionic electron tube means having a cathode, an anode and the control grid; an anode circuit connecting said anode and cathode in series and having a load impedance therein; a feed back transformer having a primary winding and a secondary winding in inductive relation; a condenser connecting one end of said primary winding to said cathode, the other end of said primary winding being connected to the anode; a grid biasing control circuit including a resistance and a capacitance, electrically connected to said secondary winding; said control grid and said cathode being connected to said control circuit so as to be on each side of said resistance; said feed back transformer and the load impedance in the anode circuit which causes a pulsating potential to be applied to the primary winding, being such as to cause the secondary winding to alternately apply a negative potential to said grid sufficiently large to block the flow of current through the electron tube, and a positive potential sufliciently large to cause saturation current to flow through said electron tube, at a frequency determined by the time constant of the resistance and capacitance in the grid control circuit; differentiating circuit means arranged to differentiate the oscillations generated by the oscillation generator; an intermittent interrupting means arranged to effectively, intermittently interrupt the output oscillations of the oscillation generator, comprising a relay shunted by acondenser connected to the anode circuit/through a resistance, said relay being arranged to simultaneously open a switch in said anode circuit in series with a power supply filter and a switch in series with said 'relaywhich is normally spring-biased into closed position, thus-'de-energizing the relay and allowing said switches to close, which causes the relay 'to be energized again and open the switches intermittently in a manner dependent upon the time constant of said interrupting means whereby the oscillations generated by the oscillation generator are caused to increase to a maximum and decrease to aminimum upon opening and closing of 'said'switch at a rate of increase and decrease dependent upon the time constant of the power supply filter.

ROBERT W. HODGSON.

8 REFERENCES CITED 'The following references are or "record inthe file of this patent:

UNITED STATES PATENTS 

